Burner



R. M. SHERMAN BURNER March 14, 1944 Filed April 18, 1940 Inventor: M.Shernza 5 Radon Patenterl Mar. 14, 1944 UNITED STATES PATENT OFFICEURNEB' Itallston'.M.. Sherman, Glastonbury, Conn.

Application dpril 18, 1940, Serial No. 330,340

3 Claims. (01. 158-87) above, without cored This invention relates toburners, and indie particularly towhat are termed combustion tu beburners, in which liquid oil is admitted to .the burner base and therevaporized, the fuel vapor being burned in an overhead-combustionchambarto which air is supplied through combustion tubes, herein in the form ofperforated tubular shells. I I

The objects of the invention are to'materially increase the capacity ofthe burnerwhenl.ope'rat-.

ing under normal conditions, to reduce the starting time or thatrequired to bring th'e'burner to such normal operating conditions,toincrease the effectiveness of the burner. in other respects, and

at the same time to simplify its construction and the expense ofmanufacture. I

These and other objects of the invention will be-b'est understood byreference to the "following description when taken in connection.withthe accompanying illustration of one specific "embodiment thereof,while its scOpe'Will be more particularly pointed out in the appendedclaims. In the drawing: I I Fig. l is a plan'view of .a burner embodyingone form of the invention, the Shellsor tubes bemg removed; I I

Fig.2 is a sectional elevation on the linex2-2 inFig. l, a portion ofthe shells being broken away; I I

Fig. 3 isa detail showing in plan section the lower part of the outershell resting within the base flange and illustrating the attachment ofthe'wick'thereto; and

Fig. 4 is an elevation showing a lower part of the outer shell with thewick attached.

Referring to the drawing and-to the embodimentiof' the invention theresubmitted for illustrative purposes, the'burner is provided with'ametallic base 5 comprising 'a fiat,""annularbottom 7 which is borderedby the outer upright annular flange or lip 9 andthe innerflange ,l I,the latter surrounding the air opening I I3 in the base. This providesbetween the two flanges'a broad annular compartment" or fuel channel,near the inner portionof which is the oil 'admission opening l5 throughwhich oil i's'supplied by a pipe connection, not shown. The base issupported by any suitable means, as by the boss ll on the cross-web l9extending across and beneath the-air opening.

This provides a' base of theutnfost simplicity, inexpensive tomanufacture, which may be formed of pressed-metal'if desired, or of.cast iron and, if thelatter, may be cast ingree'n' sand'withoiit corework. lhe base itself isentirely open from I passages, thus providingnothing but what may be easily and readily cleaned and examine d. II

Near the outside of its top, the flange ll is provided with a shoulderon which rests an annular metallic plate '2l provided with a series ofperforations 23 to constitute air admission openings.

' The plate extends outwardly to partly overlie the broad fuel channelin the'base, its outer edge s'ervingto abut against the inner walls ofthe inner combustion tube or shell '25 and to center the latter. Theshell25'compris'es a perforated sheet metal cylinder resting onsuitable'supports such as the three raised lugs or feet 26 presentedbythe flat bottom 'Tof the fuel channel, and suchthat the lower edge ofthe shell is maintained above the normal'starting level of the oil,which level -is indicatedvby dotted lines in Fig. 2.

A similar but larger-concentric cylinder 21 is removably seated on theflat bottom 7 of the fuel channeL'with theouter wallsofits'lower end inloose contact with the inner walls of the flange" 9. The two spacedshells 25 and 21 provide between them an elongated combustion chamber 29which extends from the bottom wall I of the fuel channel to thetops ofthe shells. I

-At a point spaced a short distance above the top of the flange 9 theperipheral walls of the shells each have a similar beaded or rolled formation 3|, the two'beads extending in the same direction, the bead ofthe shell 21 extending into the combustion chamber. Near the tops of theshells a similar beaded formation is provided, and a disk-shaped plate33, which may or may not have 'a small central opening 35, rests on thebead presented by the inner shell 25 so as to close or partly close thetop of the central air chamber, leaving however an annular opening inthe top of the combustion chamber for the escape of the products ofcombustion.

A burner of this general type is commonly started by igniting an oilsaturated wick, comprising'a fabricated strip of asbestos cut so as torest on edge in the fuel compartment of the base. In the illustrativeform of the invention,

such a wick 31 having a vertically corrugated formation is provided,which wich is held in fixed position on the inner lower walls of one ofthe combustion tubes, herein the outer tube 27, by means of metallicU-shaped clips 39 which are spot-welded to the inner walls of the tube.By this means the wick may be removed from the burner with the tube forexamination, cleaning, replacement or other purposes, can be conven-(such as is indicated by dotted lines in Fig. 2) by usual well-knownextraneous constant level sup The wick being then lighted, theply means.burner begins to heat, and, when the required vaporizing temperature isreached, combustion is carried on to a gradually increasing degree byvaporization of the oil more or less independently of the wick. When theburner is operating under normal conditions of full fire, the wickceases to have any substantial vaporizing function. At that stage theliquid oil should become vaporized substantially on entering the channeland the level of the liquid oil in the channel under these conditionsundergoes a corresponding drop.

Curtailment of the time required to bring the burner from its initialstarting stage to full fire is therefore dependent in large part onrapidly increasing the vaporizing temperature in the burner andparticularly by rapidly raising the temperature of the parts of the basewhich form the fuel channel therein. In the described form of burnerthis is accomplished not only by the conduction of heat to the channelwalls of the base through the walls of the shells, but also by loweringthe initial zone of combustion and intensifying such combustion in closeproximity to the bottom of the channel and to the liquid oil therein. Itwill be observed that the shell 21, which quickly becomes heated afterthe ignition of the wick, rests on the bottom of the wall I of the oilchannel and has contact with the inner wall of the channel flange 9 andis closely adjacent the wick. This arrangement provides for an efficienttransfer of th heat from the upper portions of the rapidly heating shellto the oil and to the channel walls of the base both by conduction andradiation.

The vaporizing effect in and about the base channel when the wick isignited is greatly augmented, however, by the fact that initialcombustion takes place in close proximity to the bottom of the channel.Thus, when the wick is lighted, air is being supplied to the combustionchamber, not merely through the air openings in the sides of the innerand outer shells above the level of the plate 2 I, but primary air isalso being supplied to the fuel channel in the base and to the lowermostpart of the combustion chamber, such air entering through theperforations or air inlets 23 in the plate 2| itself. Such primary airpasses into the space beneath the plate and thence through and beneaththe inner shell 25, where it fills the lowermost part of the combustionchamber and surrounds the wick.

The latter, accordingly, produces a starting flame which is not, asheretofore, confined to the region above the top edge of the wick and tothe space above the top of the base flange 9, but spreads over the sidesof the wick creating a. starting flame in the fuel channel itself at thebottom of the combustion chamber and intensifying its starting action.Initial combustion instead of being confined to that part of thecombustion chamber well above the wick, starts and spreads through thespace at the side of and about the wick. Since primary air i beingsupplied to the space in which the wick rests, the latter, for purposesof lighting, is not required to project its upper edge into that part ofthe combustion chamber above the walls of the base, and which issupplied with air through perforations in the side walls of the shells,but the wick if desired may be relatively narrow in these respects.

With the burner started and the oil becoming vaporized by contact withthe base independently of the wick, the primary air supply necessary toinitiate combustion i being brought through the perforated platedirectly into the oil channel.

- Initial combustion, therefore, not only takes place in the oil channelitself and at the very bottom portions of the shells which rest on orhave contact with the base.

This materially hastens the rapid rise in the vaporizing temperature ofthe base parts which contact with the oil and materially decreases thetime for bringing the burner up to a state of normal operation.

The supply of primary air to the fuel channel and the lowermost part ofthe combustion chamber not only materially reduces the time required forstarting the burner, but has the more important result of greatlyincreasing the oil burning capacity and the general effectiveness of theburner when the starting stage has been completed and the burner hasbeen brought to normal operation.

In operating at full fire conditions substantially the entire spaceconstituting the oil channel becomes a vaporizing space filled with oilvapor. The primary air entering through the plate 2| commingling withthe oil vapor forms a combustible mixture so that combustion begins inthat space and continues to be maintained at the lowermost part of thecombustion chamber.

This effects a marked lowering of the zone of intense combustion in thecombustion chamber during full fire operation. In the burners of theprior art, where the primary air enters through the side walls of theshell above the walls of the base, intense combustion takes place atsuch an elevated point that the shells fail to reach a state ofincandescence for some substantial distance above the base. In a burnerconstructed as described and operating under normal conditions, thewalls of the outer shell 21 are incandescent down to the flange 9 andthe walls of the shell 25 down to or below the plate 2|.

The effectiveness of a burner of this class depends to a large extent onits radiating capacity. The spread of incandescence over the lower wallsof the shell, which is gained in the present instance, greatly increasesthe area of incandescence which can be attained, and correspondinglyaugments the radiating capacity of the burner. The lowering ,of the areaof incandescence is also of importance where these burners are used asrange burners for oven heating. In burners of the prior art, due to thefact that incandescence is confined to the upper portions of the shells,it has been difficult to heat the lower part of the adjacent oven whichis located opposite the lower part of the burner. In the burner of thedescribed construction the area of incandescence is extended to thelower part of the burner where it becomes more efiective for ovenheating.

The highly heated or incandescent condition of the shells down to thepoint where they enter the base contributes to lowering the zone ofcombustion and raises the vaporizing and oil burning capacity of theburner, apart from the contributory efiect of the greater heat conductedthrough them to the walls of the base. The plate 2| itself becomeshighly heated clue to the heat radiated and conducted from the closelyadjacent incandescent walls of the shells and functions as a vaporizingplate in its action on the oil beneath the same. The primary airsupplied through the heated plate to the oil channel is in turn highlyheated, bringing the mixture of air and oil vapor in the oil channel toa point Where intense combustion is readily initiated at the bottom ofthe combustion chamber. The secondary air, which is supplied to thecombustion chamber through the side walls of the shell immediately abovethe base, also passes through the lowermost highly incandescent areas ofthe shell, so that no cool spot or checking of combustion can there takeplace which tends to occur with the admission of air thereto throughsections of the shell which have not been brought to incandescence.

The lowering of the zone of intense combustion and its initiation in thelowermost part of the combustion chamber have an important advantage inovercoming what is known as fading. This is a difficulty encounteredwhen it is attempted, as for example during the night, to maintain theburner in operation but at such a low rate as to little more than keepit lighted. Under these conditions the supply valve is very nearlyclosed. As the base cools, its vaporizin capacity decreases, and the oillevel tends to rise. This has the effect of choking or retarding thefeed of oil. The rise in oil level, however, has intensified the actionof the burner with the result that, with the partly closed valve, acondition is built up under which insufiicient oil is fed through thenearly closed valve to maintain further combustion and the burner goesout.

With the described construction, under similar conditions, thetemperature of the lower walls of the shells and of the base parts ismaintained at a higher point, preventing, under the low feed of oil, theinitial rise in oil level due to low vaporization, and theextinguishment of the burner is prevented.

Besides increasing the oil burning and heat radiating capacity of theburner and reducing the starting time, the creation of intensecombustion in the lowermost part of the combustion cham er and closelyapproximate the base, materially assists in avoiding carbonization ofthe oil in the fuel channel. The fact that the inner shell, whichbecomes more intensely heated during full fire operation (though not atthe first stage of starting) while entering the oil groove is maintainedabove the normal oil level, prevents the formation of coke or carbon onand below the shell itself, which carbon, due to the high temperature ofthe shell, would otherwise tend to form rapidly, with the obstruction ofthe free passage of the oil and oil vapor from the vaporizing chamber tothe combustion chamber. Due to this and to the large unbroken vaporizingspace in the base, the

burner may be operated for long periods without the necessity ofcleaning. It is also possible to operate the burner with heavier gradesof oil than is usual, due to the fact that its vaporizing capacity issufiicient to burn off not only the lighter but the heavier oil ends asWell, the latter of which tend to carbonize without vaporization when itis attempted to use such heavier oil in burners of the prior art wherethe vaporizing capacity is insufiicient.

While there is herein shown and described for purposes ofexemplification one specific embodiment of the invention, it will beunderstood that this is submitted for illustrative purposes only andthat extensive deviations may be made from the form, construction andrelative arrangement of parts as herein shown, all without departingfrom the principles and spirit of the invention herein described.

I claim:

1. A combustion tube oil burner having, in combination, a base formed toprovide on its upper side a broad endless fuel channel and an airadmission opening surrounded by said channel, an inner verticalperforated combustion tube enclosing an air chamber supplied with airthrough said air admission opening, an outer vertical perforatedcombustion tube surrounding said inner combustion tube in spacedrelation thereto to form a combustion chamber between them, the lowerend portions of both of said combustion tubes entering said fuel channeland extending into proximity with the bottom thereof, the innercombustion tube being materially spaced from the inner wall of said fuelchannel and having its lower edge slightly spaced from the bottom ofsaid channel, means providing an oil vaporizing and carbureting chamberwithin said fuel channel comprising a metal plate overlying the bottomof said fuel channel between the inner wall of the latter and said innercombustion tube, which plate and the portion of said inner tube belowthe plane of said plate are in substantially unobstructed heatconducting relation to the vapor space of said oil vaporizing andcarbureting chamber for freely transferring heat thereto for vaporizingoil therein, said plate being formed with openings for passage of airfrom said air chamber to said oil vaporizing and carbureting chamber foradmixture with the oil vapors in the latter to form a combustiblemixture, whereby during normal operation of the burner such combustiblemixture will be conducted beneath the lower edge of said innercombustion tube from the last mentioned chamber to the bottom of thecombustion chamber so that combustion may be maintained at the bottom ofsaid combustion chamber within said fuel channel.

2. A combustion tube oil burner according to claim 1 in which the loweredge of the inner combustion tube is spaced from the bottom of the fuelchannel by spaced lugs projecting upwardly from said bottom, upon whichlugs said edge rests.

3. A combustion tube oil burner according to claim 1 in which the fuelchannel is formed by an upstanding vertical inner flange and asurrounding upstanding vertical outer fiange both on the base, the platebeing supported by said inner flange and acting laterally to positionthe inn r combustion tube, the outer combustion tube fit ting withinsaid outer flange and being laterall positioned thereby.

RALLSTON M. SHERMAN.

